Re: Finding domain and subdomains from host name
- From: "Thrill5" <nospam@xxxxxxxxxxxxx>
- Date: Mon, 11 May 2009 15:39:47 -0400
"Peter J. Holzer" <hjp-usenet2@xxxxxx> wrote in message
news:slrnh0eeoi.phs.hjp-usenet2@xxxxxxxxxxxxxxxxxx
On 2009-05-10 17:46, Gunnar Hjalmarsson <noreply@xxxxxxxxx> wrote:
John wrote:
But, my original problem which is to locate all domains using a single
IP
address remains.
My recent searching throws up 'reverse IP' as maybe the term I should be
looking at to find all domains on a single IP.
No. All domains resolve to an IP,
No. Many domains don't have A records. Some have NS or MX or SRV or TXT
records, some don't have any records at all and serve only as containers
for their subdomains. And that's without considering specialized domains
like in-addr.arpa.
but the other way around only works accationally.
Right. There is no way to find all domains which contain an A record
with a specific IP address. The only way to do that would be to walk
recursively through the complete domain name space, but most name
servers don't allow that any more.
"Reverse lookups" typically return only the canonical name of the
interface. It is rare that a PTR lookup returns more than one result
(try "dig -x 143.130.20.2" for an example)
hp
The "in-addr.arpa" domain is where the reverse lookups are (i.e. the PTR
records). The IP address is reversed and placed into the "in-addr.arpa"
domain. For example to create a PTR record for 143.130.20.2, the actual
record is:
2.20.130.143.in-addr.arpa PTR mx.luga.at.
Just because you have created an "A" record doesn't mean that there is a
corresponding "PTR" record, they are created independently of each other. A
"PTR" is very similar to a "CNAME", in that you query a name, and a name is
returned. If a "PTR" record isn't created then there is no way to do a
reverse lookup. In a nutshell, given an IP address there is no way to find
all the domains that is associated with that IP address unless someone
created a PTR record for A record. This is very rare, as it is standard
practice to create only a single PTR record for each IP address.
.
- References:
- Finding domain and subdomains from host name
- From: John
- Re: Finding domain and subdomains from host name
- From: Mart van de Wege
- Re: Finding domain and subdomains from host name
- From: Mart van de Wege
- Re: Finding domain and subdomains from host name
- From: John
- Re: Finding domain and subdomains from host name
- From: Peter J. Holzer
- Re: Finding domain and subdomains from host name
- From: John
- Re: Finding domain and subdomains from host name
- From: Gunnar Hjalmarsson
- Re: Finding domain and subdomains from host name
- From: Peter J. Holzer
- Finding domain and subdomains from host name
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